HL OpenGL Problem

[mfw41]

I'm been having problems playing the HL games and Gunman Chronicles, I just can't seem to play them in OpenGL. When I play vengeance, the text for the beginning into looks fine then they get brighter and bigger and blurry(like the effect you get when you noclip though a door in HL and there's nothing behind it), and I also get black squares across the screen. I could play them in Direct3D but for some reason in Blue Shift and in vengeance as soon as I save I have to quit the game because I doesn't show where I am after i save, in BS I get the loading screen and in vengeance I get the background of the main menu. So i'm asking you knowledgable people for help in this problem please.